U.S. patent number 7,134,717 [Application Number 10/489,060] was granted by the patent office on 2006-11-14 for backrest for a vehicle seat.
This patent grant is currently assigned to Johnson Controls GmbH. Invention is credited to Silvio Hartlaub, Bernd Kraemer, Jan Thunnissen.
United States Patent |
7,134,717 |
Thunnissen , et al. |
November 14, 2006 |
Backrest for a vehicle seat
Abstract
The backrest of a vehicle seat having a headrest, which may be
displaced from an in-use position to a safety position by the
effect of a force generation device, and which is fixed, by means
of retaining elements extending into the backrest. The retaining
elements may be displaced relative to the backrest, under the
effect of the force generating device, by means of at least one
connector guide, from a connector into a connector side block. The
connector slide block is preferably lockable in the connector on
the displacement from the in-use position to the safety position.
One embodiment includes a rectangular connector slide block which
performs a turning movement on the displacement, as a result of
which the radial extent of the above relative to the connector is
increased thus locking the connector slide block in the connector
with a positive or non-positive fit.
Inventors: |
Thunnissen; Jan (Wanssum,
NL), Kraemer; Bernd (Zingsheim, DE),
Hartlaub; Silvio (Cologne, DE) |
Assignee: |
Johnson Controls GmbH
(Burscheid, DE)
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Family
ID: |
26010382 |
Appl.
No.: |
10/489,060 |
Filed: |
September 6, 2002 |
PCT
Filed: |
September 06, 2002 |
PCT No.: |
PCT/EP02/09965 |
371(c)(1),(2),(4) Date: |
March 09, 2004 |
PCT
Pub. No.: |
WO03/022624 |
PCT
Pub. Date: |
March 20, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040239160 A1 |
Dec 2, 2004 |
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Foreign Application Priority Data
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Sep 10, 2001 [DE] |
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201 14 944 U |
Oct 18, 2001 [DE] |
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101 50 899 |
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Current U.S.
Class: |
297/216.12;
297/216.13 |
Current CPC
Class: |
B60N
2/838 (20180201); B60N 2/888 (20180201); B60N
2/809 (20180201) |
Current International
Class: |
B60N
2/42 (20060101) |
Field of
Search: |
;297/216.12,216.13,216.14 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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29603991 |
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Mar 1996 |
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DE |
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19750375 |
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Nov 1997 |
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DE |
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19738201 |
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Apr 1998 |
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DE |
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19817980 |
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Apr 1998 |
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DE |
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19924236 |
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May 1999 |
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DE |
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19938904 |
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Aug 1999 |
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DE |
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10054793 |
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Nov 2000 |
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DE |
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20114944 |
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Sep 2001 |
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DE |
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10150899 |
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Mar 2003 |
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DE |
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0888926 |
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Jun 1998 |
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EP |
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0982186 |
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Jul 1999 |
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EP |
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WO 03/022624 |
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Mar 2003 |
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WO |
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Primary Examiner: Nelson, Jr.; Milton
Assistant Examiner: D'Adamo; Stephen
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
The invention claimed is:
1. A backrest (1) including a frame structure (2) and a
force-generating device (11) for a vehicle seat, having a head
restraint (3) which can be adjusted from an in-use position into a
safety position under action of the force-generating device (11)
which is effective in an accident situation, said head restraint
being connected to the backrest via retaining elements protruding
into the backrest, the retaining elements being displaceable
relative to the backrest (1) under the action of the
force-generating device (11) by a pair of slotted-guide mechanisms,
each of the slotted-guide mechanisms comprising: a slotted guide:
(14) and a sliding block (15) guided in the latter, wherein the
sliding block (15), when displaced from the in-use position into
the safety position, executes a rotational movement enabling the
sliding block to be locked in one of a frictional and form-fitting
manner in the slotted guide (14), wherein the retaining elements
have at least two guide rods (5) which are guided in a
longitudinally displaceable and fixable manner in guide sleeves
(6), the guide sleeves being connected to each other via a strut
(9) and the force-generating device (11) engaging, on one end, on
the strut and, at another end, on the frame structure (2) of the
backrest (1).
2. The backrest as claimed in claim 1, wherein the sliding block is
configured in a rectangle cross-section.
3. The backrest as claimed in claim 1 wherein the slotted guide
(14) can be deformed by the edges of the sliding block (15) in a
manner of a catch when the safety position is reached.
4. The backrest as claimed in claim 1 wherein the slotted guide
(14) has, in the direction of displacement, a first section (20.1)
which runs essentially vertically and is adjoined at the top by a
second section (20.2) which runs obliquely relative to the first
section (20.1).
5. The backrest as claimed in claim 4, wherein the second section
(20.2) is aligned to the rear relative to the first section
(20.1).
6. The backrest as claimed in claim 1 wherein the slotted guide
(14) tapers in the direction of displacement.
7. The backrest as claimed in claim 1 wherein the slotted-guide
mechanism has a convex slotted guide (14) and the sliding block
(15) supported in the slotted guide in at least two locations
spaced apart from each other.
8. The backrest as claimed in claim 1 wherein the retaining
elements can be displaced through the frame structure by a
leadthrough and the slotted-guide mechanism, which is spaced apart
from the leadthrough, in the backrest (1), the slotted guide (14)
selectively running obliquely, relative to a straight line (G)
connecting the sliding block (15) to the leadthrough in the in-use
position.
9. The backrest as claimed in claim 8, wherein the leadthrough is
configured above the slotted-guide mechanism and the slotted guide
(14) runs aligned to the rear relative to the straight line
(G).
10. The backrest as claimed in claim 1 wherein the retaining
elements can be displaced via said two slotted-guide mechanisms in
the backrest each having said sliding block, with said slotted
guides running obliquely, at least in some regions, relative to a
straight line (G) connecting the two sliding blocks in the in-use
position, and spaced apart from each other and directed counter to
each other.
11. The backrest as claimed in claim 1 wherein the force-generating
device (11) comprises a compressed-gas store.
12. The backrest as claimed in claim 1 wherein the force-generating
device (11) comprises a pyrotechnic igniting charge (21).
13. The backrest as claimed in claim 1 wherein the slotted guides
(14) of each of the slotted-guide mechanisms are connected to the
frame structure (2) of the backrest (1) and the sliding blocks (15)
are connected to the retaining elements.
14. The backrest as claimed in claim 1 wherein the force-generating
device (11) comprises a spring element, which can be locked under
pretension by means of a locking device (10).
15. The backrest as claimed in claim 14, wherein the locking device
(10) can be released by a pyrotechnic activator (18).
16. The backrest as claimed in claim 14, wherein the locking device
(10) can be released by an electromagnetic activator.
17. The backrest as claimed in claim 14, wherein the spring element
is one of a tension spring (12) and a compression spring (22).
18. A backrest (1) including a frame structure (2) and a
force-generating device (11) for a vehicle seat, having a head
restraint (3) which can be adjusted from an in-use position into a
safety position under action of the force-generating device (11)
which is effective in an accident situation, said head restraint
being connected to the backrest via retaining elements protruding
into the backrest, the retaining elements being displaceable
relative to the backrest (1) under the action of the
force-generating device (11) by a slotted-guide mechanism, the
slotted-guide mechanism comprising: a slotted guide: (14) and a
sliding block (15) guided in the latter, wherein the sliding block
(15), when displaced from the in-use position into the safety
position, executes a rotational movement enabling the sliding block
to be locked in one of a frictional and form-fitting manner in the
slotted guide (14), wherein the retaining elements comprise at
least two guide rods (5) which are connected to each other via a
strut (9), the force-generating device (11) engaging, at one end,
on the strut and, at another end, on the frame structure (2) of the
backrest (1).
19. The backrest as claimed in claim 18 wherein the
force-generating device (11) comprises a spring element, which can
be locked under pretension by means of a locking device (10).
20. The backrest as claimed in claim 19, wherein the spring element
is one of a tension spring (12) and a compression spring (22).
21. The backrest as claimed in claim 19, wherein the locking device
(10) can be released by a pyrotechnic activator (18).
22. The backrest as claimed in claim 19, wherein the locking device
(10) can be released by an electromagnetic activator.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application claims benefit to International Application No.
PCT/EP02/09965 filed on Sep. 6, 2002, and published in the English
language under PCT Article 21(2); German application no. DE 201 14
944.3, filed Sep. 10, 2001, and DE 101 50 899.9 filed Oct. 18, 2001
all of which are incorporated herein by these references.
BACKGROUND
The invention relates to a backrest for a vehicle seat, having a
head restraint which can be adjusted from an in-use position into a
safety position under the action of a force-generating device which
is effective in an accident situation, said head restraint being
connected to the backrest via retaining elements protruding into
the backrest.
Even in the case of a relatively minor rear-end impact, vehicle
occupants are exposed to the risk of suffering an overextension of
the cervical vertebra under the effect of accident-induced
acceleration forces. Although head restraints which are connected
rigidly to the backrest of the vehicle seat are able to reduce the
risk of injury, they are situated, for reasons concerned with
comfort, too far away from the head in the in-use position in order
to prevent injuries in the neck region effectively. The same is
also true if the head restraint has been set to the correct height,
corresponding to the vehicle occupant's height, by displacement of
its guide rods in the guide sleeves of the backrest.
In order to improve the protection of the occupant, safety devices
have therefore been developed which have a head restraint which can
be pivoted automatically from the in-use position into a safety
position in the event of a rear-end impact, as a result of which
its distance from the occupant's head is reduced. Systems of this
type are referred to as a "passive head restraint" if the
adjustments into the safety position are brought about by the
acceleration forces of the occupant acting on the seat. By
contrast, if the generator of the adjusting force is fed from a
separate power source, the safety system is provided with an
"active" head restraint.
The laid-open specification DE 197 38 201 A1 discloses a backrest
of the generic type for a vehicle seat. The passive head restraint
has guide rods which protrude into the backrest and are guided in a
longitudinally displaceable and fixable manner in two spaced-apart
sleeves for the purpose of adjusting the height. The lower sleeve
is connected directly to the frame structure of the backrest via a
rotary joint while the upper sleeve is articulated on the frame
structure via a toggle-lever mechanism which is angled in the
in-use position. In the event of an accident, the toggle lever is
stretched, as a result of which the guide rods rotate about the
axis of the lower rotary joint and pivot the head restraint in the
direction of the vehicle occupant's head. A leaf spring which is
arranged in the lumbar region of the backrest and is curved in the
in-use position is used to generate force, the leaf spring being
straightened in an accident under the action of the acceleration of
the occupant, as a result of which the distance between its ends is
increased. This lengthening is transmitted via a mechanism to the
toggle lever and changes its position in the previously described
manner.
This variant basically has the disadvantage that, depending on the
sitting position of the occupant, the leaf spring is insufficiently
lengthened. Furthermore, the height of the head restraint, which is
frequently set in quite a low position for reasons concerned with
comfort, cannot be changed when adopting the safety position.
A backrest having an active head restraint is disclosed in the
laid-open specification DE 199 38 904 A1. The backrest is
constructed in two parts, the lower part being connected to the
seat part of the vehicle seat in a conventional manner, the upper
part, in contrast, being pivotable together with the head restraint
relative to the lower part about an axis running transversely with
respect to the longitudinal axis of the vehicle from an in-use
position into a safety position. The torque required for this is
generated by a compression spring which acts on a lever, is
tensioned in the in-use position of the seat and locked by means of
a latching device. The acceleration forces which are produced in a
rear-end impact are detected by a vehicle crash sensor. A control
device releases the latching device by triggering a pyrotechnic
activator as soon as acceleration values which exceed a
predetermined threshold value are measured.
This device satisfies the requirements placed on it in respect of
the safety of the vehicle occupants, but is associated with being
relatively complex in terms of design.
SUMMARY
The invention is based on the object of providing a backrest with a
safety device which is effective and is simply constructed in terms
of design and by means of which both the distance between the head
restraint and the occupant's head and the height of the head
restraint relative to the in-use position can be influenced in the
safety position.
According to the invention, the object is achieved in the case of a
backrest of the generic type by the retaining elements being
displaceable relative to the backrest under the action of the
(passive or active) force-generating device by means of at least
one slotted-guide mechanism comprising a slotted guide and a
sliding block guided in the latter.
In contrast with the rotation of the head restraint about a fixed
axis, which rotation is known from the prior art, the slotted-guide
mechanism permits the retaining elements to be guided as desired,
with the result that their upwardly directed displacement can be
combined with any desired pivoting movement.
According to one preferred variant of the invention, the
slotted-guide mechanism can have a slotted guide with a convex
recess and sliding blocks supported in the recess at at least two
locations which are spaced apart from each other. When the sliding
blocks are displaced, a pivoting movement is inevitably generated
and this can be associated with a simultaneous height adjustment of
the head restraint.
According to a further advantageous variant of the invention, the
retaining elements can be displaced in each case through the frame
structure by means of a leadthrough and a slotted-guide mechanism,
which is spaced apart from it, in the backrest, the recess of the
slotted guide running obliquely, at least in some regions, relative
to a straight line connecting the sliding block to the leadthrough.
The oblique profile of the recess in the slotted guide causes the
sliding block to change its horizontal position at the same time as
an upwardly directed displacement, so that the retaining elements
overall execute a pivoting movement, the axis of rotation of which
runs horizontally through the leadthroughs in a fixed position with
respect to the frame structure. This design requires a particularly
small amount of space if the leadthrough is arranged above the
slotted-guide mechanism and the recess of the slotted guide runs
rotated to the rear relative to the straight line. The sliding
block is therefore also shifted to the rear during the upwardly
directed displacement, which causes the head restraint to pivot
forward.
As an alternative, it is conceivable to arrange the retaining
elements displaceably in each case via two slotted-guide mechanisms
in the backrest, which mechanisms are spaced apart from each other
or merge into each other, the recesses of the slotted guides
running obliquely, at least in some regions, relative to a straight
line connecting the sliding blocks, and spaced apart from each
other and opposed to each other.
In order to improve the function of the head restraint, it is
proposed, according to a further preferred variant of the
invention, for the sliding block, when displaced from the in-use
position into the safety position, to be able to be locked in the
recesses of the slotted guide. This can be brought about with
little complexity in terms of design by the fact that the sliding
block, when displaced, executes a rotational movement, as a result
of which its radial extent directed toward the recess is enlarged
thus enabling the sliding block to be locked in a frictional or
form-fitting manner in the recess. The recess can advantageously
also taper in the direction of displacement thus enabling the
sliding block to be locked in a frictional or form-fitting manner
in the recess.
The displacement forces caused by the force-generating device can
be transferred into the head restraint in a particularly favorable
manner if the retaining elements comprise at least two guide rods
which are connected to each other via a strut, the force-generating
device engaging, on the one hand, on the strut and, on the other
hand, on the frame structure of the backrest.
In order to bring about a simple adaptation of the height of the
head restraint to the vehicle occupant's height, it is
alternatively proposed that the retaining element has at least two
guide rods which are guided in a longitudinally displaceable and
fixable manner in guide sleeves, the guide sleeves being connected
to each other via a strut and the force-generating device engaging,
on the one hand, on the strut and, on the other hand, on the frame
structure of the backrest. For height adjustment by means of the
occupant, the guide rods are displaced together with the padded
part in the guide sleeves and are fixed relative to them in the
desired position. By contrast, when the safety position is adopted,
the guide sleeves are shifted together with the guide rods, as a
result of which the padded part takes up the desired position.
A spatially favorable variant of the invention is possible by the
fact that the slotted guides of the slotted-guide mechanism are
connected in each case to the frame structure of the backrest and
the sliding blocks are connected in each case to the retaining
elements. This design also enables the head-restraint mass, which
has to be accelerated when the safety position is adopted, to be
kept low.
The adjusting force can be generated with little complexity and in
principle in a reversible manner by means of a spring element, in
particular a tension spring or compression spring, which can be
locked under pretension by means of a locking device. The
activation can take place via a pyrotechnic device which reacts
particularly spontaneously, or by means of an electromagnetic
activator, which has the advantage of multiple use.
By contrast, a particularly high acceleration can be obtained by
the force-generating device comprising a compressed-gas store or,
in particular, a pyrotechnic igniting charge.
DESCRIPTION OF DRAWINGS
The figures illustrate one variant of the invention by way of
example and
In the figures:
FIG. 1 shows a rear view of a backrest designed in accordance with
the invention, in the in-use position
FIG. 2 shows the backrest according to FIG. 1 in the longitudinal
section X--X
FIG. 3 shows a corresponding longitudinal section through the
backrest after the safety position has been reached
FIG. 4 shows one design of the slotted guide and sliding block
according to claim 7, in the in-use position
FIG. 5 shows the variant according to FIG. 4 in the safety
position
FIG. 6 shows a longitudinal section through another backrest
according to the invention, in the in-use position
FIG. 7 shows the backrest according to FIG. 6 in the safety
position
FIG. 8 shows a longitudinal section through a further variant of
the invention, in the in-use position
FIG. 9 shows the backrest according to FIG. 8 in the safety
position
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
The backrest 1 which is depicted in part in FIG. 1 comprises a
metal frame structure 2 which is provided in use with padding
materials and upholstery fabrics (not illustrated). In the
exemplary embodiment, the cross-section of the frame structure 2 is
of U-shaped design, as is apparent from FIGS. 2 and 3.
In its upper region, the backrest 1 is provided with a head
restraint 3 which comprises a padded part 4 and two vertically
downwardly extending guide rods 5. The guide rods 5 are guided in a
longitudinally displaceable manner in guide sleeves 6 which, for
their part, are arranged in leadthroughs, designed as recesses 7,
through the frame structure 2. In order to set the height of the
padded part 4 relative to the frame structure 2, a catch 8 is
released, so that the guide rods 5 can subsequently be displaced
upward or downward in the guide sleeves 6. The position of the two
components relative to each other is then fixed again by the catch
8.
The guide sleeves 6 are connected to each other by a horizontally
arranged strut 9. They are arranged in a manner such that they can
be displaced upward in the recesses 7, which are situated in the
upper limb of the frame structure 2, and in a manner such that they
can be rotated about a horizontal axis which runs transversely with
respect to the longitudinal axis of the vehicle and is customarily
referred to as the Y-axis of the vehicle. In the in-use position,
the guide sleeves 6 are retained in the height position illustrated
by means of a locking device 10.
For the basic construction of a locking device of this type
reference is made to the prior art cited at the beginning.
The locking device 10 keeps a force-generating device 11 in the
form of a compression spring 12 under tension, the force-generating
device being supported, on the one hand, on the lower limb of the
laterally open U-profile of the frame structure 2 and, on the other
hand, engaging on the strut 9.
Two slotted guides 14 which are incorporated in sheet-metal plates
13 are embedded in the frame structure 2 and circular sliding
blocks 15 arranged in the strut 9 engage in them. By means of this
engagement and the mounting of the guide sleeves 6 in the recesses
7, the head restraint 3 is basically mounted securely in the frame
structure 2 in the in-use position.
The slotted guides 14 are inclined relative to the vertical in such
a manner that the sliding blocks 15 guided in them and therefore
also the strut 9 are shifted to the rear at the same time as a
displacement upward. For this reason, the slotted guide 14 runs at
a corresponding slope relative to an imaginary straight line G
connecting the sliding blocks 15 to the associated recesses 7 in
the in-use position.
In the event of a rear-end impact, an electronic control device 16
ignites a pyrotechnic activator 18 as a function of the
acceleration values measured by a crash sensor 17, said activator,
for its part, releasing the locking device 10. Under the action of
the expanding compression spring 12, the strut 9 and the guide
sleeves 6 connected to it are displaced upward. The simultaneously
occurring, rearwardly directed shifting of the strut 9 furthermore
causes the guide sleeves 6 to undergo a rotational movement by
means of which those parts of the guide rods 5 which protrude out
of the frame structure 2 are pivoted toward the head 19 of the
vehicle occupant. The distance between the padded part 4 and the
head 19 is therefore reduced as desired in the safety position.
FIGS. 4 and 5 show one possible design of the slotted guide 14 and
sliding block 15 with which a self-locking of the guide can be
brought about when the safety position has been reached. The
slotted guide 14 comprises a first section 20.1 which runs
essentially vertically and is upwardly adjoined by an oblique,
second section 20.2 which is rotated to the rear relative to the
first section 20.1. In the exemplary embodiment, the width of the
slotted guide 14 remains constant.
The rectangular sliding block 15 is arranged displaceably in the
slotted guide 14 and, in the in-use position, is situated in the
first section 20.1 with side surfaces aligned parallel to the
slotted guide 14, but, in the safety position, is displaced into
the second section 20.2. During this displacement the sliding block
15 additionally undergoes a rotational movement. In a departure
from the variant illustrated in FIGS. 2 and 3, the rectangular
sliding block 15 increases its width in the slotted guide 14 during
this rotation, as a result of which it is locked in said slotted
guide. This effect can be designed in such a manner that the
sliding block 15 is only slightly clamped in the slotted guide 14
and can be displaced again into the position according to FIG. 4.
However, depending on the forces of displacement and the
geometrical design of the guide, a form-fitting locking can also be
brought about, in which the sliding block 15 uses its edges to
deform the slotted guide 14 in the manner of a catch when the
safety position has been reached.
In the case of the backrest according to FIGS. 6 and 7, the guide
rods 5, to which the padded part 4 of the head restraint 3 is
fastened, are directly guided in convexly curved slotted guides 14
via in each case two sliding blocks 15.1 and 15.2 which are spaced
apart from each other. Under the action of a force-generating
device 11 in the form of one of a pyrotechnic activator, an
electromagnetic activator, a compressed gas store and a pyrotechnic
igniting charge 21 the sliding blocks 15 are displaced in the
arcuate slotted guide 14, as a result of which both a shifting of
the height and also a rotational movement of the padded part 4 are
brought about. In the case of this head restraint 3, the adaptation
to the occupant's height can be undertaken by displacing the padded
part 4 relative to the guide rods 5.
FIGS. 8 and 9 show a last design of the invention. The guide rods 5
of the head restraint 3 depicted there are held by sliding blocks
15.1 and 15.2 which are guided in each case in separate slotted
guides 14.1 and 14.2. The recesses of the slotted guides 14.1 and
14.2 run obliquely, at least in some regions, relative to an
imaginary straight line G connecting the sliding blocks 15.1 and
15.2 in the in-use position, and offset with respect to each other
and directed counter to each other. By means of the lower slotted
guide 14.2, the lower end of the guide rod 5 is deflected to the
rear during the displacement into the safety position; in contrast,
the upper end of the guide rod 5 is deflected forward by the
mirror-inverted position of the upper slotted guide 14.1. During a
displacement upward, which is initiated by a force-generating
device 11 in the form of a tension spring 22, the head restraint 3
performs a pivoting movement toward the head 19 of the occupant.
The slotted guides 14 furthermore narrow in the direction of
displacement from the in-use position into the safety position, so
that the sliding blocks 15, when displaced, become wedged in the
slotted guide 14 and lock the head restraint 3 in the safety
position.
* * * * *